 /*******************************************************************************
  * Copyright (c) 2006, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.ui.internal.commands;

 import java.util.ArrayList ;
 import java.util.Collection ;
 import java.util.HashSet ;
 import java.util.Map ;
 import java.util.Set ;

 import org.eclipse.core.commands.Category;
 import org.eclipse.core.commands.Command;
 import org.eclipse.core.commands.IExecutionListener;
 import org.eclipse.core.commands.IHandler;
 import org.eclipse.core.commands.ParameterType;
 import org.eclipse.core.commands.ParameterizedCommand;
 import org.eclipse.core.commands.SerializationException;
 import org.eclipse.core.commands.common.NotDefinedException;
 import org.eclipse.ui.commands.IElementReference;
 import org.eclipse.ui.commands.ICommandService;
 import org.eclipse.ui.menus.UIElement;

 /**
  * A command service which delegates almost all responsibility to the parent
  * service.
  * <p>
  * This class is not intended for use outside of the
  * <code>org.eclipse.ui.workbench</code> plug-in.
  * </p>
  *
  * @since 3.2
  */
 public class SlaveCommandService implements ICommandService {

     private Collection fExecutionListeners = new ArrayList ();

     /**
      * The collection of ICallbackReferences added through this service.
      *
      * @since 3.3
      */
     private Set fCallbackCache = new HashSet ();

     private ICommandService fParentService;

     /**
      * The scoping constant added to callback registrations submitted through
      * this service.
      *
      * @since 3.3
      */
     private String fScopingName;

     /**
      * The object to scope. In theory, the service locator that would find this
      * service.
      *
      * @since 3.3
      */
     private Object fScopingValue;

     /**
      * Build the slave service.
      *
      * @param parent
      * the parent service. This must not be <code>null</code>.
      */
     public SlaveCommandService(ICommandService parent, String scopeName,
             Object scopeValue) {
         if (parent == null) {
             throw new NullPointerException (
                     "The parent command service must not be null"); //$NON-NLS-1$
 }
         fParentService = parent;
         fScopingName = scopeName;
         fScopingValue = scopeValue;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#addExecutionListener(org.eclipse.core.commands.IExecutionListener)
      */
     public void addExecutionListener(IExecutionListener listener) {
         if (!fExecutionListeners.contains(listener)) {
             fExecutionListeners.add(listener);
         }
         fParentService.addExecutionListener(listener);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#defineUncategorizedCategory(java.lang.String,
      * java.lang.String)
      */
     public void defineUncategorizedCategory(String name, String description) {
         fParentService.defineUncategorizedCategory(name, description);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#deserialize(java.lang.String)
      */
     public ParameterizedCommand deserialize(
             String serializedParameterizedCommand) throws NotDefinedException,
             SerializationException {
         return fParentService.deserialize(serializedParameterizedCommand);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.services.IDisposable#dispose()
      */
     public void dispose() {
         if (!fExecutionListeners.isEmpty()) {
             Object [] array = fExecutionListeners.toArray();
             for (int i = 0; i < array.length; i++) {
                 removeExecutionListener((IExecutionListener) array[i]);
             }
             fExecutionListeners.clear();
         }
         if (!fCallbackCache.isEmpty()) {
             Object [] array = fCallbackCache.toArray();
             for (int i = 0; i < array.length; i++) {
                 unregisterElement((IElementReference) array[i]);
             }
         }
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getCategory(java.lang.String)
      */
     public Category getCategory(String categoryId) {
         return fParentService.getCategory(categoryId);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getCommand(java.lang.String)
      */
     public Command getCommand(String commandId) {
         return fParentService.getCommand(commandId);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getDefinedCategories()
      */
     public Category[] getDefinedCategories() {
         return fParentService.getDefinedCategories();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getDefinedCategoryIds()
      */
     public Collection getDefinedCategoryIds() {
         return fParentService.getDefinedCategoryIds();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getDefinedCommandIds()
      */
     public Collection getDefinedCommandIds() {
         return fParentService.getDefinedCommandIds();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getDefinedCommands()
      */
     public Command[] getDefinedCommands() {
         return fParentService.getDefinedCommands();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getDefinedParameterTypeIds()
      */
     public Collection getDefinedParameterTypeIds() {
         return fParentService.getDefinedParameterTypeIds();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getDefinedParameterTypes()
      */
     public ParameterType[] getDefinedParameterTypes() {
         return fParentService.getDefinedParameterTypes();
     }

     public final String getHelpContextId(final Command command)
             throws NotDefinedException {
         return fParentService.getHelpContextId(command);
     }

     public final String getHelpContextId(final String commandId)
             throws NotDefinedException {
         return fParentService.getHelpContextId(commandId);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#getParameterType(java.lang.String)
      */
     public ParameterType getParameterType(String parameterTypeId) {
         return fParentService.getParameterType(parameterTypeId);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#readRegistry()
      */
     public void readRegistry() {
         fParentService.readRegistry();
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#removeExecutionListener(org.eclipse.core.commands.IExecutionListener)
      */
     public void removeExecutionListener(IExecutionListener listener) {
         fExecutionListeners.remove(listener);
         fParentService.removeExecutionListener(listener);
     }

     public final void setHelpContextId(final IHandler handler,
             final String helpContextId) {
         fParentService.setHelpContextId(handler, helpContextId);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#refreshElements(java.lang.String,
      * java.util.Map)
      */
     public void refreshElements(String commandId, Map filter) {
         fParentService.refreshElements(commandId, filter);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#registerElementForCommand(org.eclipse.core.commands.ParameterizedCommand,
      * org.eclipse.ui.menus.UIElement)
      */
     public IElementReference registerElementForCommand(
             ParameterizedCommand command, UIElement element)
             throws NotDefinedException {
         if (!command.getCommand().isDefined()) {
             throw new NotDefinedException(
                     "Cannot define a callback for undefined command " //$NON-NLS-1$
 + command.getCommand().getId());
         }
         if (element == null) {
             throw new NotDefinedException("No callback defined for command " //$NON-NLS-1$
 + command.getCommand().getId());
         }

         ElementReference ref = new ElementReference(command.getId(), element,
                 command.getParameterMap());
         registerElement(ref);
         return ref;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#registerElement(org.eclipse.ui.commands.IElementReference)
      */
     public void registerElement(IElementReference elementReference) {
         fCallbackCache.add(elementReference);
         elementReference.getParameters().put(fScopingName, fScopingValue);
         fParentService.registerElement(elementReference);
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.ui.commands.ICommandService#unregisterElement(org.eclipse.ui.commands.IElementReference)
      */
     public void unregisterElement(IElementReference elementReference) {
         fCallbackCache.remove(elementReference);
         fParentService.unregisterElement(elementReference);
     }
 }

